| A new refractory Ni7Nb2 phase identified in Laves eutectic regions by TEM study | |
| Ge, Hualong1,2; Xing, Weiwei3; Chen, Bo3; Hu, Xiaobing4; Zheng, Shijian1,5; Liu, Kui3; Ma, Xiuliang1 | |
| Corresponding Author | Zheng, Shijian(sjzheng@hebut.edu.cn) |
| 2021-08-01 | |
| Source Publication | ACTA MATERIALIA
 |
| ISSN | 1359-6454 |
| Volume | 214Pages:10 |
| Abstract | The dissolution behavior of gamma/Laves eutectic within a typical Ni-based superalloy (Inconel 718) was investigated by in-situ and conventional transmission electron microscopy (TEM) techniques. The results show that the Laves phase dissolved firstly at 700 degrees C, but a new Ni7Nb2 phase possessing similar composition with delta-Ni3Nb phase precipitated near Laves phase did not dissolve at temperatures up to 950 degrees C. The new Ni7Nb2 phase with lattice parameters: a=0.473 nm, b=0.794 nm, c=1.21 nm and beta=91.3 degrees, shows a C2/m space group symmetry. The crystal structure of the new Ni7Nb2 phase can be understood by "triple layers" as the Ni7Zr2-type structure does, stacking perpendicular to the (001) planes. Instead of stacking with one single shift vector s corresponding to the Ni7Zr2-type structure, the stacking sequences of the new Ni7Nb2 can be characterized by alternate occurrence of +s and -s. Moreover, the structural change of gamma/Laves eutectic constituent before and after heat treatment was investigated. The Ni7Nb2 could remain after heat treatment. Since the experimental Ni7Nb2 structure was shown to be unstable in the Ni-Nb binary system by calculation, it is suggested that Zr, Si and Co promote the formation of Ni7Nb2 phase in superalloys according to the segregation behaviors of elements. Moreover, as Ni7Zr2 is considered to be detrimental to the mechanical properties, Ni7Nb2 phase should also have negative influences and should be eliminated through possible approaches. The finding of the new phase should shed light on the microstructural controlling and heat treatment process formulating of superalloys. (C) 2021 Acta MaterialiaInc. Published by Elsevier Ltd. All rights reserved. |
| Keyword | Nickel-based superalloys Inconel 718 In-situ transmission electron microscopy Laves phase Eutectic Ni-Nb phase |
| Funding Organization | National Natural Science Foundation of China ; Key Project of Natural ScienceFoundation of Liaoning Province, China |
| DOI | 10.1016/j.actamat.2021.116985 |
| Indexed By | SCI |
| Language | 英语 |
| Funding Project | National Natural Science Foundation of China[51771201] ; Key Project of Natural ScienceFoundation of Liaoning Province, China[20180510059] |
| WOS Research Area | Materials Science ; Metallurgy & Metallurgical Engineering |
| WOS Subject | Materials Science, Multidisciplinary ; Metallurgy & Metallurgical Engineering |
| WOS ID | WOS:000670363500010 |
| Publisher | PERGAMON-ELSEVIER SCIENCE LTD |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.imr.ac.cn/handle/321006/159933 |
| Collection | 中国科学院金属研究所 |
| Corresponding Author | Zheng, Shijian |
| Affiliation | 1.Chinese Acad Sci, Inst Met Res, Shenyang Natl Lab Mat Sci, Shenyang 110016, Peoples R China 2.Univ Sci & Technol China, Sch Mat Sci & Engn, Hefei 230026, Peoples R China 3.Chinese Acad Sci, Inst Met Res, Shenyang 110016, Peoples R China 4.Northwestern Univ Evanston, Dept Mat Sci & Engn, Evanston, IL 60208 USA 5.Hebei Univ Technol, Sch Mat Sci & Engn, Tianjin Key Lab Mat Laminating Fabricat & Interfa, Tianjin 300130, Peoples R China |
| Recommended Citation GB/T 7714 | Ge, Hualong,Xing, Weiwei,Chen, Bo,et al. A new refractory Ni7Nb2 phase identified in Laves eutectic regions by TEM study[J]. ACTA MATERIALIA,2021,214:10. |
| APA | Ge, Hualong.,Xing, Weiwei.,Chen, Bo.,Hu, Xiaobing.,Zheng, Shijian.,...&Ma, Xiuliang.(2021).A new refractory Ni7Nb2 phase identified in Laves eutectic regions by TEM study.ACTA MATERIALIA,214,10. |
| MLA | Ge, Hualong,et al."A new refractory Ni7Nb2 phase identified in Laves eutectic regions by TEM study".ACTA MATERIALIA 214(2021):10. |
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